Valve seat grinder



y 1933. E. A, HALL 1,906,263

VALVE SEAT GRINDER Filed Feb. 25, 1932 INVENTOR.

6134; a, NW;

ATTORNEY5 Patented May 2, 1933 UNITED STATES PATENT OFFICE ERNEST A. HALL, OF TOLEDO OHIO, ASSIGNOR TO THE HALL MANUFACTURING COMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO VALVE SEAT GRINDER Application filed February 25, 1932. Serial No. 595,139.

This invention relates to valve seat grinders but more particularly to grinders of the type having a pilot adapted to be mounted in the valve stem guide and a grinder which rotates and revolves about the pilot during the grinding operation.

An object of this invention is to attach the grinding or abrading element to the mounting so that it may be readily secured rigidly in the desired relation to'the pilot and adjustable so that in the event of wear the element may be tightened and retain the same relation to the pilot, thereby insuring that valve seats will be properly ground in 1 each instance.

Other objects and advantages will hereinafter appear and an embodiment of the invention is shown by way of illustration on the accompanying drawing in which Figure 1 is a vertical elevation partly in section of the lower portion of a valve seat grinder showing the same mounted in working relation to a valve seat;

Figure 2 is an enlarged elevation partly in section of the sleeve for the grinding element;

Figure 3 is a vertical sectional elevation of the grinding element showing the sleeve in elevation; and

element and sleeve.

The illustrated embodiment comprises a valve seat grinder of the type shown and described in my Patent No. 1,760,493, issued May 27th, 1930. Detail illustration and description of the tool is not considered necessary here. Suffice it to say that the abrading or grinding stone 10 has a tapered grinding surface 11 for grinding a valve seat S, and

the stone 10 rotates about a pilot 12, which has a tapered end 13 adapted to extend into a valve stem guide or bearing G, thereby providing a support for the tool in proper relation to the valve seat S. The stone 10 is eccentric to the pilot 12, and, in addition to being rotated, it also revolves traveling slowly about the valve seat and in this manner progressively grinds the seat.

A mounting or casing 14 for the driving parts is provided with a sleeve 15 which en- Figure 4 is a top plan view of the grinding gages the pilot 12. The pilot is formed with a relatively shallow helical groove 16 which is adapted to retain lubricant and also provides a relief passage for air when the tool is slid down upon the pilot. Projecting outwardly from the mounting 14 and disposed outside of the sleeve 15 is a tubular extension 17, the outer end 18 of which has an inwardly extending lip 18 located slightly beyond the end of the s eeve.

The stone 10 is formed with a central cavity 19 and disposed therein in an annular metallic ring or sleeve 20 having an external annular groove 21 and a tapered surface 22. Portions of the exterior are roughened or knurled. The ring is held in place by suitable cement 23 which fills in the groove 21 and coacts with the roughened surfaces to retain the ring securely in place.

Formed on the inside of the ring or sleeve 20'at the inner end are screw threads 24 which engage threads on the inner portion of the extension 17. Extending outwardly from the threaded portion 24 is an inwardly inclined or tapered surface 25 which contacts v with a similar tapered surface 26 formed on the extension 17 The degree of taper may vary but a 10 taper has been found most satisfactory.

It is apparent that when the stone 10 is 30 attached to the extension 17 the tapered surfaces 25 and 26 cause the stone to be accurate- 1y positioned with respect to the pilot 12.

en wear occurs between the sleeve 20 and the extension 17, the stone 10 may be screwed on tighter and the tapered surfaces maintain the stone in the desired centered position so that it can accurately and efliciently perform its work. This arrangement militates against the trouble and difficulty heretofore experienced in keeping the stone properly positioned.

Numerous changes in details of construction, arrangement and operation may be effected without departing from the spirit of 5 the invention.

What I claim is:

A valve seat grinder comprising a tool having a tapering abradin face, a mounting forthe tool, mechanism or concomitantly rotating and revolving said mounting so that the tool engages the valve seat at substantially a single point and travels progressively around the seat, means for detachably connecting said abrading tool to said mounting, said connecting means comprising surfaces on said tool and mounting respectively tapering upwardly and outwardly from the lower end thereof and in position to receive the thrust approximately perpendicularly from said abrading surface, and substantially cylindrical threaded surfaces on said tool and mounting res ectively dis osed adjacent the upper ends 0 said tapere surfaces and in a region free from thrust relation to said working face.

In testimony whereof I have hereunto signed my name to this s ecification.

- ER ST A. HALL. 

